1. Field of the Invention
The present invention relates to a machining-related information generating apparatus which automatically generates machining-related information including tool path data indicative of a tool traveling path and cutting conditions and other machining-related data to be used in an NC machine tool, and to a numerical controller having the machining-related information generating apparatus.
2. Description of the Prior Art
An apparatus for automatically generating tool path data has hitherto known, which employs a CAM (computer aided manufacturing) technique to generate the tool path data on the basis of product design data generated by CAD (computer aided design).
The design data generated by the CAD (hereinafter referred to as xe2x80x9cCAD dataxe2x80x9d) includes configuration data indicative of the final configuration and dimensions of a product to be obtained after machining (e.g., coordinates data and mathematical expression data), and data indicative of dimension lines. After extracting the product configuration data from the CAD data, the tool path data generating apparatus receives data required for the generation of the tool path data, for example, data of configurational characteristics of the product indicative of whether the product has a round portion, a rectangular portion, a cylindrical portion, a prismatic portion, a convex surface or a concave surface and data of machining methods indicative of to-be-used tools and cutting conditions, which are inputted from an input device by an operator. The tool path data generating apparatus generates the tool path data on the basis of the inputted data and the configuration data extracted from the CAD data.
However, the conventional tool path data generating apparatus is designed so that the operator inputs the data of the product configurational characteristics and the data of the machining methods required for the generation of the tool path data, thereby requiring much time for the data input and hence for the machining of the product. In addition, it is difficult to perfectly prevent human errors in the data input, resulting in production of defective products or damages to jigs and tools. This is a serious problem particularly in the case of machining for production of a uniquely customized product such as a mold.
Where an NC machining program is generated on the basis of the tool path data generated by the tool path data generating apparatus and a machining operation is performed on the basis of the NC machining program by an NC machine tool, the NC machine tool may fail to provides an expected result due to chattering of the tools and an overload during the machining. In such a case, it is necessary to perform time-consuming trouble-shooting and then correct the NC machining program. For the correction of the NC machining program, the tool path data generating process should retrospectively be performed from the initial stage thereof by the tool path data generating apparatus. This requires much time before outputting NC machining program again, thereby reducing the productivity with much downtime of the machine tool.
In the conventional tool path data generating apparatus, the data of the to-be-used tools and the cutting conditions for the generation of the tool path data is inputted by the operator as described above. Therefore, the inputting operator has to preliminarily determine the types of the tools and tool holders to be used and machining conditions such as tool settings (e.g., tool length), and a machining operator has to prepare the tools according to the machining conditions determined by the inputting operator when actually performing a machining operation. To this end, the inputting operator conventionally formulates a worksheet prescribing the machining conditions (machining operation information).
However, the formulation of the worksheet requires much time, and it is preferred to streamline the worksheet formulating operation as much as possible to save the machining time. Particularly in the case of the machining for the production of the uniquely customized product (e.g., mold) which often entails a great machining loss, it is desirable to streamline the worksheet formulating operation. Further, human errors are liable to occur in the worksheet formulating operation, causing a serious accident.
In view of the foregoing, it is an object of the present invention to provide a machining-related information generating apparatus which can speedily and correctly generate tool path data on the basis of CAD data and automatically generate machining-related information required for actual machining, and to provide a numerical controller having the machining-related information generating apparatus.
In accordance with the present invention to achieve the aforesaid object, there is provided a machining-related information generating apparatus, which automatically generates machining-related information including tool path data indicative of tool traveling paths and cutting conditions and other machining-related data to be used in an NC machine tool, the apparatus comprising: a process/machining model data generating section which extracts at least characteristic data indicative of three-dimensional configurational characteristics of a product from product configuration data generated by CAD, then generates process data indicative of machining processes and machining areas for the respective machining processes on the basis of the extracted characteristic data, and generates stock blank data indicative of a configuration of a stock blank and machining model data indicative of machining models for the respective machining processes; process/machining model data storage section for storing therein the characteristic data, the process data, the stock blank data and the machining model data prepared by the process/machining model data generating section; tool database storing therein tool data related to tools; machining condition database storing therein machining condition data indicative of cutting conditions according to stock blank materials and tool materials and machining methods according to characteristic configurations; a machining-related information generating section which generates tool path data indicative of tools to be used in the respective machining processes, cutting conditions to be employed in the respective machining processes, machining methods to be employed in the respective machining processes and tool traveling paths to be employed in the respective machining processes on the basis of the process data, the stock blank data and the machining model data stored in the process/machining model data storage section, the tool data stored in the tool database and the machining condition data stored in the machining condition database, then generates virtual workpiece configuration data indicative of workpiece configurations to be obtained after completion of the respective machining processes, and generates machining operation information data indicative of machining operation information on the basis of the process data, the stock blank data, the tool path data and the virtual workpiece configuration data; machining-related information storage section for storing therein the data generated by the machining-related information generating section; and output means for outputting the data stored in the machining-related information storage section to the outside.
In the machining-related information generating apparatus according to the present invention, the process/machining model data generating section extracts only the configuration data required for the generation of the tool path data from product design data generated by the CAD by excluding data such as indicative of dimension lines unnecessary for the generation of the tool path data, and then extracts at least the characteristic data indicative of the three-dimensional configurational characteristics of the product from the extracted configuration data. The three-dimensional configurational characteristics herein indicate how the product is three-dimensionally configured, e.g., whether the product has a round portion, a rectangular portion, a cylindrical portion, a prismatic portion, a convex surface or a concave surface.
Then, the process data indicative of the machining processes and the machining areas for the respective machining processes are generated on the basis of the extracted characteristic data. More specifically, the machining areas are defined as corresponding to the respective characteristic configurations, and then machining processes (e.g., rough machining, semi-finish machining or finish machining) are assigned to the respective machining areas. Alternatively, areas to be subjected to machining with the use of the same tool are regarded as a single machining area, and a machining process (e.g., rough machining, semi-finish machining or finish machining) is assigned to the machining area. The stock blank data indicative of the stock blank configuration and the machining model data indicative of the machining model configurations after completion of the respective machining processes are generated on the basis of the configuration data of the product. For determination of the stock blank configuration and the machining model configurations, finishing allowances in the respective machining processes are sequentially offset from a final product configuration. The characteristic data, the process data, the stock blank data and the machining model data are stored in the process/machining model data storage section.
The machining-related information generating section generates the tool path data indicative of the tools to be used in the respective machining processes, the cutting conditions to be employed in the respective machining processes, the machining methods to be employed in the respective machining processes, the tool traveling paths to be employed in the respective machining processes on the basis of the process data, the stock blank data and the machining model data stored in the process/machining model data storage section, and the tool data stored in the tool database and the machining condition data stored in the machining condition database. The machining methods are herein intended to include machining modes such as contour line machining, scanning line machining, circular interpolation, linear interpolation and cutting directions, a feed pitch for repetitive machining in a predetermined machining cycle, and a machining sequence for machining in the respective machining areas.
Further, the virtual workpiece configuration data indicative of the workpiece configurations to be obtained after the completion of the respective machining processes are generated, and the machining operation information data indicative of the machining operation information is generated on the basis of the process data and the stock blank data generated in the process/machining model data generating section, the tool path data and the virtual workpiece configuration data. The machining operation information is herein intended to include at least one of tool information required for a preparatory operation, information indicative of use of a cutting fluid, and machining-related information such as cutting conditions, estimated machining times, tool wear amounts, tool life expectancies, and a workpiece configuration to be obtained after completion of machining.
The tool path data and the machining operation information data thus generated are stored as the machining-related information in the machining-related information storage section and, as required, outputted to the outside on an image basis or a text basis in a displayed form or a printed form, or on an electronic data basis.
In accordance with the present invention, there is no need for an operator to input the data of the characteristic configurations of the product and the data of the machining methods indicative of the to-be-used tools and the cutting conditions for the generation of the tool path data, so that the data input time is obviated. Therefore, the tool path data can speedily be generated, thereby effectively speeding up the machining of the product. Further, human errors in the data input can be eliminated, thereby preventing production of defective products and damages to jigs and tools which may otherwise occur due to the input errors. The effect of the present invention is particularly remarkable in the case of machining for production of a uniquely customized product such as a mold.
The tool path data is herein intended to include data such as of tool traveling paths, tool rotation speeds and tool feeding speeds required for operating the NC machine tool, and means data which serves as a base for generating motion data required for executing an NC machining program and for directly driving a servo mechanism of the NC machine tool.
Since the machining-related information including the information required for the preparatory operation for the machining can automatically be generated, human errors in a worksheet formulating operation can be prevented to streamline the worksheet formulating operation. By utilizing the machining-related information thus generated, the preparatory operation for the machining can easily be performed in a shorter time. Further, a machining time can be estimated, so that an optimum time slot (daytime or nighttime) can be selected for the machining. If a machining operation is expected to be completed in a short time, the machining operation may be performed during an operator-attended operation period and, after the completion of the machining operation, the operator can perform the next workpiece machining operation or the next preparatory operation. Thus, the productivity can be improved. On the other hand, if a machining operation is expected to require much time, the machining operation may be performed during a nighttime non-attended operation period. Further, the number of the tools required for the machining and the machining time can be estimated, thereby making it possible to preliminarily calculate costs for the machining of the workpiece. Therefore, cost estimation can promptly be provided.
The machining-related information generating apparatus may further comprise an NC machining program generating section which converts the tool path data generated by the machining-related information generating section into an NC machining program, which is in turn outputted to the outside. The machining-related information generating apparatus may further comprise a motion data generating section which converts the tool path data into motion data, which is in turn outputted to the outside. With this arrangement, the machining program and the motion data thus generated can directly be inputted on-line to a numerical controller of the NC machine tool, or inputted to the numerical controller with the use of a recording medium such as a floppy disk. Thus, the generation of the tool path data can be carried out with no link-up to the NC machine tool, i.e., on an off-line basis, so that the utilization factor of the NC machine tool can be increased. The motion data herein means data required for directly driving the servo mechanism of the NC machine tool.
The tool path data thus generated may immediately be implemented and processed for the machining.